Faster fastball isn’t translating into more strikeouts for Bass

Anthony Bass’ change in mechanics could be the cause in his increase in velocity. ( Melissa Phillip / Houston Chronicle )

Anthony Bass’ fastball has seen an uptick of nearly 2 mph this season, sitting at 95.21 compared to 93.42 mph, per BrooksBaseball.net. The Astros righty reliever worked in the offseason to improve his delivery — using backside more, not letting his arm drift — and he believes that’s what’s led to the welcome increase. He’s using the fastball more often, understandably.

But a bit puzzling is why Bass doesn’t have more strikeouts. In 18 innings entering Tuesday, he had fanned just four batters. He entered the year averaging 6.5 strikeouts per nine innings, but this year has averaged just two per nine.

Bass said that he, pitching coach Brent Strom and bullpen coach Craig Bjornson discussed this very topic on Tuesday, and the belief is that his slider is part of the problem.

“They know that I’m coming at them 95 so they’re swinging right away, but also my breaking pitch right now it’s like a wipeout pitch,” Bass said. “(Adding) more lateral break to it will allow me to get more swings and misses. Right now it’s just short, and they’re fouling it off.”

The pitch is acting more like a cutter right now, Bass said, and to counteract that, he’s going to alter his grip on the pitch. There’s definite evidence that the slider isn’t the swing-and-miss pitch it used to be. Last year, about 42 percent of swings on the slider resulted in a swing in a miss. This year, it’s 25 percent.

Last year, just over 27 percent of swings on Bass’ slider were fouled off. This year, it’s nearly 35 percent.